摘要：
# Write your MySQL query statement below --题意：删除重复的邮箱，保留重复中邮箱id最小的 --逆向思维，删除每个邮箱中不是最小的 DELETE FROM person WHERE id NOT IN ( SELECT need.id FROM ( SELE 阅读全文
摘要：
SELECT d.Name AS 'Department', e1.Name AS 'Employee', e1.Salary FROM Employee e1 JOIN Department d ON e1.DepartmentId = d.Id WHERE --子查询 逆向思维 3 > (SEL 阅读全文
摘要：
import java.util.ArrayList; import java.util.List; /** * Given an array nums of n integers and an integer target, are there elements * a, b, c, and d 阅读全文
摘要：
import java.util.ArrayList; import java.util.LinkedList; import java.util.List; /* * Given a string containing digits from 2-9 inclusive, return all p 阅读全文